It has been well known that a color diffusion transfer photographic light-sensitive material comprises an interlayer to prevent an oxidation product of a developing agent formed by development of one light-sensitive layer from diffusing into and staining other color-sensitive light-sensitive layers or dye providing compound-containing layers. It has also been known that the interlayer contains a color stain inhibitor for this purpose.
Typical examples of such a color stain inhibitor are hydroquinone compounds. As such hydroquinone compounds there have been proposed mono-n-alkylhydroquinones in U.S. Pat. Nos. 2,360,290, 2,419,613, 2,403,721, and 3,960,570, monobranched alkylhydroquinones in U.S. Pat. No. 3,700,453, JP-A-49-106329, JP-A-50-156438 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), and West German Patent OLS No. 2,149,789, dialkylsubstituted hydroquinones in U.S. Pat. Nos. 2,728,659, 2,732,300, 3,243,294, and 3,700,453, British Patent 752,146, JP-A-50-156438, JP-A-53-9528, JP-A-54-29637, and JP-B-50-21249 (the term "JP-B" as used herein means an "examined Japanese patent publication"), arylhydroquinones in U.S. Pat. No. 2,418,613, hydroquinones nucleus-substituted by electrophilic groups such as acyl group, nitro group, cyano group, formyl group and halogenated alkyl group in U.S. Pat. No. 4,198,239, hydroquinones substituted by aliphatic acylamino group, ureido group, urethane group or the like in U.S. Pat. No. 4,198,239, hydroquinones substituted by sulfonamido groups in JP-A-59-202465, and hydroquinones containing electrophilic groups in JP-A-57-22237, such as hydroquinone substituted by carbamoyl groups.
Only color stain inhibitors having a sufficient nondiffusibility are practically significant. For example, dialkylhydroquinone color stain inhibitors each needs to contain a total of 30 or more carbon atoms in its dialkyl portion. Most such hydroquinone compounds are in the form of oil. If such an oil compound is incorporated in the interlayer in a large amount, it softens the film or oozes out and diffuses into other layers. This requires the use of a binder for supporting the film (e.g., gelatin) in a large amount, resulting in an unnecessarily thick film.
On the other hand, it is rather commercially essential that a color diffusion transfer photographic light-sensitive material provides a short time required between the beginning of processing and the completion of images, i.e., fast image formation. In order to expedite the image completion, various approaches have been proposed. In particular, it is the most essential and effective to provide a thinner light-sensitive material, i.e., shorten the diffusion distance over which a dye diffuses into and reaches the image-receiving layer. To this end, it is effective to reduce the binder (e.g., gelatin) content in each layer. However, the reduction of the binder content causes some disadvantages. For example, the film strength is deteriorated. The adhesion of one layer to its adjacent layers is lowered, causing the layer to be peeled off. Furthermore, emulsified materials or emulsions present in layers lower their supporting capability, causing compounds to migrate to adjacent layers during a prolonged period of time.
Among these disadvantages, the deterioration in the film strength and the adhesion of one layer to adjacent layers become remarkable particularly in photographic materials of the process wherein the image-supporting portion is peeled off the film unit after the completion of images. In particular, if the interlayer (color stain inhibitor) can be peeled off its adjacent layer by a power equal to or less than that required to peel the release layer, the image-supporting portion cannot be surely peeled off the release layer but can be peeled off the interlayer. This is a critical defect that disables the view of images in the image-receiving layer.
Among various peel processes, an example wherein the film properties of the interlayer are the most important is described in JP-A-63-226649. In this process, the basic structure comprises a white support, an image-receiving layer, a release layer, a cyan color material layer, a silver halide emulsion layer, an interlayer, a magenta color material layer, a silver halide emulsion layer, an interlayer, a yellow color material layer, a silver halide emulsion layer, and a protective layer coated sequentially on a support. In this structure, images cannot be viewed unless the image-receiving layer can be surely peeled off the release layer. However, if the conventional interlayer is used, the image-receiving layer is often peeled off the interlayer. It has been thus keenly desired to improve the film strength of the interlayer.
The process described in JP-A-59-220727, too, has a big disadvantage in that the image receiving layer is peeled off the interlayer.
In a laminated integrated type light-sensitive material as described in JP-B-46-16356, JP-B-48-33697, JP-A-50-13040, and British Patent 1,330,524 or an ordinary peel apart process, it is keenly required to expedite the image completion. Thus, it has been desired to provide an interlayer capable of giving a thinner layer without deteriorating the film properties (color stain inhibiting layer).
It is also effective to provide an interlayer capable of giving a thinner layer as well as eliminating the need for a partition layer for preventing mixing between the interlayer and the dye providing compound layer. A partition layer as described in JP-B-60-15267 is adapted to improve the raw preservability of light-sensitive materials. Such a partition layer serves to prevent mixing between the interlayer and the dye providing compound layer. Therefore, if an interlayer which can be hardly mixed with the dye providing compound layer is provided, such a partition is no longer needed. Thus, it has been desired to provide an interlayer having excellent raw preservability.